/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;

import java.util.Collection;

import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public abstract class AbstractCollectionTester<E>
        extends AbstractContainerTester<Collection<E>, E>
{

    // TODO: replace this with an accessor.
    protected Collection<E> collection;

    @Override
    protected Collection<E> actualContents()
    {
        return collection;
    }

    // TODO: dispose of this once collection is encapsulated.
    @Override
    protected Collection<E> resetContainer(Collection<E> newContents)
    {
        collection = super.resetContainer(newContents);
        return collection;
    }

    /**
     * @see AbstractContainerTester#resetContainer()
     */
    protected void resetCollection()
    {
        resetContainer();
    }

    /**
     * @return an array of the proper size with {@code null} inserted into the middle element.
     */
    protected E[] createArrayWithNullElement()
    {
        E[] array = createSamplesArray();
        array[getNullLocation()] = null;
        return array;
    }

    protected void initCollectionWithNullElement()
    {
        E[] array = createArrayWithNullElement();
        resetContainer(getSubjectGenerator().create(array));
    }

    /**
     * Equivalent to {@link #expectMissing(Object[]) expectMissing}{@code (null)} except that the call
     * to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
     *
     * @param message message to use upon assertion failure
     */
    protected void expectNullMissingWhenNullUnsupported(String message)
    {
        try
        {
            assertFalse(message, actualContents().contains(null));
        }
        catch (NullPointerException tolerated)
        {
            // Tolerated
        }
    }
}
